William I. Traeger graduated from Stanford University in 1901 and later attended law school at the University of Southern California. He began his career coaching football at Pomona College and Occidental College before transitioning to law enforcement as a deputy United States Marshal and deputy sheriff for Los Angeles County. Traeger was admitted to the bar in 1909 and served as the first president of the Los Angeles County Peace Officers' Association. He was appointed Sheriff of Los Angeles County in 1921, where he implemented significant reforms, including the reorganization of the county jail and the establishment of honor camps for first-time misdemeanor offenders.

William I. Traeger's career reflects a blend of law enforcement and progressive criminal justice reform, hinting at an ideologically agile approach. His establishment of honor camps and employment services for ex-offenders demonstrates a surprising progressive stance within a traditionally conservative field. Traeger's rhetorical style likely emphasizes practical, results-driven governance, as evidenced by his jail reorganization and community-focused initiatives.